CN108136896A - Transmission device and electric drive unit having a transmission device - Google Patents

Abstract

The invention relates to a transmission device having at least an input, an input stage, a load stage, a carrier and at least two output shafts, wherein: the input shaft is a first sun wheel which is rotatable about a central axis of the transmission, the input stage has a first sun wheel and a first planet wheel which is radially spaced from the central axis, the first sun wheel and the first planet wheel are coupled to one another via a first transmission connection, the load stage is formed by second planet wheels and a ring gear, one of the first planet wheels and one of the second planet wheels are each carried by a carrier in a rotationally fixed manner to one another and rotatable about a common first planet axis which is radially spaced from the central axis, the ring gear is held azimuthally fixed on the transmission housing and forms a first tooth mesh with the second planet wheel, the axis of symmetry of the ring gear is the central axis, the carrier is connected rotationally fixed to a differential cage of the transfer case, the carrier is rotatable in the transmission housing about the central axis relative to the input shaft, and-the carrier is coupled with the output shaft via a second gearing action connection of the transfer case. The invention also relates to an electric drive unit having a transmission device of this type.

Description

Transmission device and electric drive unit with transmission device

technical field

The invention relates to a transmission having at least an input, an input stage, a load stage, a carrier and at least two output shafts, wherein:

- the input shaft is the first sun gear rotatable around the central axis of the transmission,

- the input stage has a first sun gear and a first planet gear spaced radially from the central axis,

- the first sun gear and the first planet gears are coupled to each other via a first gear action connection (Wirkverbindung),

- the load stage is formed by the second planetary gear and ring gear,

- one of the first planet wheels and one of the second planet wheels are respectively carried by the carrier in such a manner that they are connected to each other in a rotation-proof manner and are rotatable about a common first planet axis radially spaced apart from the central axis ,

- the ring gear, whose axis of symmetry is the central axis, is held azimuthally fixedly on the transmission housing and forms a first tooth mesh with the second planetary mechanism,

- the carrier is connected in a rotationally fixed manner to the differential cage of the transfer case,

- the bracket is rotatable in the transmission housing in a manner rotatable about the central axis relative to the input shaft, and

- The carrier is coupled to the output shaft via the second gearing connection of the transfer case.

The invention also relates to an electric drive unit with a transmission of this type.

Background technique

US 6 401 850 B1 shows an electric drive unit of this type. These electric drive units are often used as modules for driving axles in electric vehicles or hybrid vehicles with all-wheel drive. The transmission mechanism is equipped with a reduction stage and a differential. The reduction stage is characterized by a planetary gear with a double planetary gear. The sun gear of the planetary gear is connected to the rotor shaft of the electric motor and meshes with the first planetary gear set of the double planetary gear. The second planetary gear set of the double planetary mechanism forms a tooth mesh with the ring gear. The ring gear is fixed on the housing of the drive unit. A planetary carrier is connected to the differential cage of the differential, which carries the double planetary gear in a rotatable manner. The differential is a bevel gear differential, and the driven wheel of the bevel gear differential is connected with the driven shaft via a plug shaft. Each output shaft is operatively connected to a driven wheel of a driven axle.

Contents of the invention

The object of the present invention is to provide a transmission device and an electric drive unit which can be configured variably with regard to the transmission ratio and are designed to be compact.

This task is achieved according to the subject-matter of claim 1 .

It is provided according to the invention that the first gear effect connection has at least one third planetary gear integrated into the input stage.

The invention relates to a transmission device into which a transfer case is integrated. The transfer case is installed longitudinally or transversely in the vehicle. The gear unit is preferably used in electrically driven or hybrid vehicles. The electric motor and transmission are housed in the housing. The rotor shaft has an axis of rotation on the central shaft and is connected to the input shaft of the transmission.

The characteristics of an electric drive are essentially determined by adapting the transmission ratio to the characteristic curve of the electric motor that drives it. This is especially difficult when the transmission has only a fixed transmission ratio. Important characteristics are gradeability, acceleration, efficiency (energy consumption) and maximum achievable speed. It is not possible to satisfy all these properties optimally when selecting the transmission ratio. The optimal gear ratio for the vehicle's maximum gradeability is often different than the desired value for maximum final speed or energy efficiency. Optimization of the transmission ratio is therefore extremely important. Furthermore, these requirements may also differ depending on the type of vehicle in which the drive unit is used. The vehicle type is, for example, a city vehicle, a mini, subcompact or compact car, an SUV, or the like. The constraints imposed by the narrow installation space and the design of the toothing when designing the transmission are often contrary to the above-mentioned requirements. With the invention, compared with the prior art known so far, more design and variation possibilities are available in the narrowest installation space. Instead of using one planetary gear set previously, the transmission ratio of the input stage can be adapted to different vehicle requirements via a combination of two planetary gear sets. The shaft drive ratio and the final drive ratio (Endübersetzung) can be designed in a variety of ways.

The third planet wheels are each (like the other planet wheels) carried by the carrier in such a manner that they can rotate about a planet axis radially spaced apart from the central axis. The third planet gear is doubly engaged and for this purpose simultaneously engages the first sun gear and the first planet gear. The first planetary gear is a double planetary mechanism. The additional set of planetary gears is therefore arranged in the input stage in the power flow between the sun gear, which functions as the power input of the transmission, and the double planetary gear. Furthermore, it is provided that the toothing of the first planet wheel has more teeth than the toothing of each second planet wheel. The toothing of each second planet wheel has more teeth than the toothing of the third planet wheel. With this type of arrangement, in particular in drive units whose electric motors rotate at high speeds of 12,000 to 16,000 rpm, overall transmission ratios of 6 to 8 can be realized in the narrowest installation space. The invention accordingly provides an electric drive unit which has a gear arrangement according to the invention as a first gearing connection.

The second active connection of the transmission system, namely the transfer case, can be embodied as a bevel gear differential or in any other manner. A configuration of the present invention provides that the transfer gear is a planetary differential and has a wheel set with a fourth planetary gear, a wheel set with a fifth planetary gear, a second sun gear and a third sun gear. The third sun gear is arranged coaxially with the second sun gear on the central axis. Each fourth planet wheel forms a fourth tooth mesh with the second sun gear and each fourth planet wheel forms a fifth tooth mesh with the fifth planet wheel. The fourth planet wheel is roughly as wide as the second sun wheel. The fifth planet gear is axially at least twice as wide as the fourth planet gear, so that the fifth planet gear forms a sixth tooth mesh with the third sun gear. The fourth planet wheel is therefore also referred to as a short planet wheel and the wider planet wheel as a long planet wheel. The second sun gear is operatively connected to the first of the two output shafts, and the third sun gear is operatively connected to the second of the two output shafts.

In a transfer case, the number of teeth of the toothing of the planet gears and the axial spacing of the planet axes of the planet gears from the intermediate shaft can be different or the same in the individual planet gear sets. The number of teeth of the sun gears of the transfer case can be the same or different from each other. In the sense of the present invention, a transfer case is understood to be a transmission in which the introduced power is continuously distributed proportionally to two output shafts, for example two driven axles, during straight-line travel. Alternatively, a transfer case in the sense of the invention is a differential of an axle in which the torque is divided equally between the two output shafts when driving straight ahead without slipping between the two output shafts. on the output shaft.

The embodiment of the invention provides for the differential of the axle that the sun gear has the same number of teeth and that the two planetary gear sets of the planetary differential also have the same toothing. What can be achieved with this refinement is that advantageously the same drive behavior is provided in the vicinity of the wheels in the narrow installation space to the left and right of the axle.

The axially available installation space between the wheels of the driven axle is determined for the size of the transmission with a coaxial arrangement of planetary stages. It is usually sized awkwardly. Therefore, the design of the present invention provides that the planetary gears of the double planetary mechanism and the planetary gears of the two planetary gear sets of the transfer box and the sun gear are all arranged radially on the teeth configured as ring gears. within the circle. In this case, the planet wheels of one of the planetary gear sets can protrude partially axially from the ring gear. In this case, the toothing of the planet wheels with the ring gear, the tooth meshing of the planet wheels of the planetary transfer case with one another, and the tooth meshing of a set of planet wheels with the sun wheel of the transfer case lie in a toothing plane. The tooth plane is an imaginary radial plane that intersects the central axis perpendicularly. Due to such radial nesting of two planetary stages, despite the additional planetary stages, the installation space required in the axial direction remains approximately the same or equal to that of the known prior art. Keep it smaller than that.

The configuration of the present invention provides that the planetary gears of the double planetary mechanism that form tooth meshes with the ring gear are at least partially sunk radially into each other on the circumferential side of one wheel set or two wheel sets of the transfer case. In the circumferential gap between spaced planetary gears. As a result, the installation space required in the radial direction can also advantageously be kept small.

For the purpose of transmitting a rotational movement via the teeth in a gear connection, the toothings of the gears are positively mated to one another. Proceeding from the ideal situation in which the tooth with the highest load is loaded over its entire tooth width in the tooth mesh, for example in the case of spur gears, the average tooth mesh is through the tooth center, that is to say the axial direction of the teeth meshing with each other Extend half of the width. Commonly located in a gearing plane means that the average tooth meshing is jointly located in a radial plane that intersects perpendicularly to the axis of rotation of the gearwheel. This also applies to gears that are double-occupied or multiple-occupied, ie gears that simultaneously form tooth meshes with more than two gears. In this case, two or more average tooth meshes lie in a common toothing plane. Thus, for example, the sun gear is always multiple occupied by a set of planet gears. A further example forms the short planets of the transfer case described above. Furthermore, the tooth meshes of any desired number of gear pairs can lie in a common toothing plane, even if the gear pairs do not form tooth contact with each other. What is ignored here is that the tooth centers of toothings that lie in a toothing plane but do not form a common toothing may be axially offset slightly relative to each other due to tolerances. It is also not important here whether the toothing widths of the gear wheels lying in a toothing plane are different.

Two types of gears that are double-occupied or multiple-occupied are obtained. One type is characterized by the previously described gears with two or more even tooth meshes in one tooth plane. Another type of doubly occupied gear is formed by a spur gear meshing with two or more gear teeth, wherein the average tooth meshes are offset from each other axially, ie in the direction along the axis of rotation of the gear. Correspondingly, the mean tooth meshing is located in the axially adjacent toothing plane, although it is located on one gear wheel. The prerequisite here is that the toothing in the case of a double-occupied gear has the same tooth geometry in the axial direction. The latter distinguishes this gear from a stepped or double planetary mechanism. Examples for such double-occupied gear wheels are the short planet wheels of the transfer case, which in one toothing plane simultaneously mesh with the sun gear and each with the long planet wheels of the other planetary gear set. The long planet gear is a special case of a double planetary mechanism, because it meshes with the short planet gear in one tooth plane and with the sun gear in the adjacent tooth plane, that is, it can be formed by Or two gears with different teeth.

The carrier is preferably formed from a single carrier section or housing part and is thus at the same time planetary carrier and differential cage. In this way, a cost-effective and space-saving design can advantageously be achieved.

Description of drawings

The invention is explained in more detail below with the aid of examples. in:

FIG. 1 shows a simplified and not to scale structure of an electric drive unit 1 ;

FIG. 2 shows an exemplary embodiment of the transmission device 2 used in the drive unit 1 in a general view with a partial sectional view through the planetary carrier 3 ;

FIG. 3 shows an exploded view of the transmission device 2;

FIG. 4 shows a front view of the interior of the transmission device 2 without the side panels of the brackets;

FIG. 5 shows a simplified and schematic representation of the gear wheels of the gear unit 2 from the rear side of the view shown in FIG. 4 .

Detailed ways

FIG. 1 : The electric drive unit 1 consists of an electric motor 4 , a transmission 2 and a housing 14 . The electric motor 4 and the transmission 2 are housed in a housing 14 . The rotor shaft 5 a of the rotor 5 of the electric machine is connected to the input of the gear unit 2 . The input of the transmission shaft is the sun gear S1, which is seated on the axial extension of the rotor shaft 5a. The output of the gear unit is the two output shafts A1 and A2. The output shaft A1 is coupled with the sun gear S2 of the transfer case and the output shaft A2 is coupled with the sun gear S3. The rotor shaft 5 a is a hollow shaft through which the first output shaft A1 passes axially. Furthermore, the first output shaft A1 passes through the first sun gear S1. The transmission system 2 is divided into an input stage ES and a load stage LS as well as a transfer case VG. An essential component of input stage ES, load stage LS and transfer case VG is carrier 3 with carrier plate 3 a, differential cage 3 b and carrier plate 3 c. The carrier 3 is mounted rotatably about a central axis 10 in a housing 5 .

FIGS. 1 and 3 : The first gear effect connection described by the input stage ES has the carrier plate 3 a, the two sets of planetary gears P1 and P3 and the first sun gear S1. The first planetary gear P1 and the second planetary gear P2 are respectively components of a double planetary mechanism DP in a set of double planetary mechanisms DP. The load stage LS is formed by the wheel set of the second planetary gear P2 and the ring gear H. The transfer case VG has a differential cage 3b and a carrier plate 3c and a transmission action connection formed by the second sun gear S2, the third sun gear S3, the wheel set of the fourth planetary wheel P4, and the wheel set of the fifth planetary wheel P5 . The sun gears S1 , S2 and S3 are located rotatably relative to each other on the central axis 10 .

FIG. 3 : Planetary wheels P1 and P2 are combined to form a double planetary mechanism DP and have a common planetary axis 6 . The planet wheels P3 , P4 and P5 are rotatable about the planet axes 7 , 8 or 9 on the planet pins 11 , 12 or 13 and are mounted at a radial distance from the central axis 10 .

Figures 1, 2, 4 and 5: The second planetary gear P2 forms a first tooth mesh ZE1 with the ring gear H. The first sun gear S1 forms a second tooth mesh ZE2 with the third planetary gears P3 in the first toothing plane VE1 ( FIG. 1 ), wherein each third planetary gear P3 is in the same toothing plane VE1 simultaneously with each other The first planet wheels P1 form a third toothing ZE3. In the toothing plane VE2, the toothing ZE1 of the ring gear H with the second planet wheel P2, the short fourth planet wheel P4 with the second sun wheel S2, and the short fourth planet wheel P4 with a fifth planet wheel P5 each , ZE4 or ZE5. The second planetary gear P2 , the fourth planetary gear P4 and the second sun gear S2 are arranged radially within the ring gear H, which is designed as a ring gear, that is to say surrounded by the ring gear. The ring gear H is fastened to the housing 5 . The long fifth planet gear P5 is doubly engaged and, in addition to the tooth mesh ZE5 , also forms a sixth tooth mesh ZE6 with the third sun gear S3 (see FIGS. 1 and 5 ). Each second planet wheel P2 is sunk radially in each case in the interspace between the fourth planet wheel P5 and the fifth planet wheel P5 which are spaced apart from one another on the circumferential side.

List of reference signs

Claims (10)

1. drive apparatus (2) at least has input terminal (E), input stage (ES), load stage (LS), transfer gear (VG), stent (3) and at least two output shafts (A1, A2), wherein：

The input terminal (E) is the first sun gear (S1) that can be rotated around the axis of centres (10) of the drive apparatus (2),

The input stage (ES) has first sun gear (S1) and the first row being radially spaced apart with central axial line (10) Star-wheel (P1),

First sun gear (S1) connects via the first gearing with first planetary gear (P1) and is coupled to each other,

The load stage (LS) is formed by the second planetary gear (P2) and gear ring (H),

One of them first planetary gear (P1) and one of them second planetary gear (P2) with resist to each other connection with the relative rotation and The mode that can be rotated around planet axis that is common, being radially spaced apart with central axial line (10) is held respectively by the stent (3) It carries,

Gear ring (H) orientation regularly keeps and forms the first tooth engagement with the second planetary mechanism (P2), the gear ring The axis of symmetry is the central axial line (10),

The stent (3) is anti-to be connect with the relative rotation with the differential mechanism cage of the transfer gear (VG) (3b),

The stent (3) can rotate relative to the first sun gear (S1) around the central axial line (10),

And the stent (3) joins via the second gearing connection of the transfer gear (VG) with the output shaft (A1, A2) It connects,

It is characterized in that, the first gearing connection is integrated into the third line star-wheel in the input stage at least one set (P3)。

2. drive apparatus according to claim 1, which is characterized in that the third line star-wheel (P3) with can around radially with The mode of central axial line (10) the second planet axis (7) rotation spaced apart is carried by the stent (3) and with described first Sun gear (S1) forms the second tooth engagement (ZE2), and each the third line star-wheel (P3) and each first planetary gear (P1) shape Into third tooth engagement (ZE3).

3. drive apparatus according to claim 1, which is characterized in that the second gearing connection passes through fourth planet (P4), fifth line star-wheel (P5), the second sun gear (S2) and third sun gear (S3) formation are taken turns, wherein, the third sun Wheel (S3) and the second sun gear (S2) be coaxially disposed on the central axial line (10) and each fourth line star-wheel (P4) with Second sun gear (S2) form the 4th tooth engagement (ZE4) and each fourth line star-wheel (P4) respectively with a fifth line star It takes turns (P5) and forms the 5th tooth engagement (ZE5), and wherein, the third sun gear (S3) is formed with the fifth line star-wheel (P5) 6th tooth engagement (ZE6), and here, second sun gear (S2) and the first output shaft in two output shafts (A1, A2) (A1) effect connection, and the third sun gear (S3) is acted on the second output shaft (A2) in two output shafts (A1, A2) Connection.

4. drive apparatus according to claim 3, which is characterized in that not only form the first tooth engagement with the gear ring (H) (ZE1) the second planetary gear (P2), and the fourth line star-wheel (P4), second sun gear (S2), the 4th tooth are nibbled It closes (ZE4) and the 5th tooth engagement (ZE5) is arranged radially between the central axial line (10) and the gear ring (H).

5. drive apparatus according to claim 3, it is characterised in that：With being co-located in the first teeth portion plane (VE1) The second tooth engagement (ZE2) and third tooth engagement (ZE3)；It is nibbled with the first tooth being co-located in the second teeth portion plane (VE2) Close (ZE1), the 4th tooth engagement (ZE4) and the 5th tooth engagement (ZE5)；And with the be located in third teeth portion plane (VE3) Six tooth engagements (ZE6), wherein, each teeth portion plane (VE1, VE2, VE3) be respectively it is imaginary and with the central axis (10) Vertically intersecting sagittal plane.

6. drive apparatus according to claim 3, which is characterized in that the fourth line star-wheel (P4) and the fifth line star Wheel (P5) is carried on the branch in a manner of it can be rotated rotating around respective third planet axis (8) or fourth planet axis (9) On frame (3).

7. electric drive unit (1), at least has：Housing (5)；Being arranged in the housing (5) has armature spindle (5a) Motor (4) and drive apparatus as described in the preamble according to claim 1 (2), wherein, the motor (4) and the transmission Equipment 2 is contained in the housing (5), and the armature spindle (5a) has the rotation axis on the axis of centres (10) and with the One sun gear (S1) connects, which is characterized in that the first gearing connection is with the third planet being integrated into input stage (ES) Take turns (P3), wherein, the third line star-wheel (P3) in the first teeth portion plane (VE1) respectively with first sun gear (S1) simultaneously Respectively tooth engagement is formed with the first planetary gear (P1).

8. electric drive unit according to claim 7, it is characterised in that：With second connected in the second gearing too The 4th tooth engagement (ZE4) between sun wheel (S2) and fourth line star-wheel (P4)；It is and each with being connected in the second gearing One fourth line star-wheel (P4) and by the 5th tooth engagement (ZE5) between the fifth line star-wheel (P5) of dual holding, wherein, first Tooth engagement (ZE1), the 4th tooth engagement (ZE4) and the 5th tooth engagement (ZE5) in the second common teeth portion plane (VE2), In, the fourth line star-wheel (P4) and the fifth line star-wheel (P5) are with can be rotating around respective third planet axis (8) or The mode of four planet axis (9) rotation is carried on stent (3).

9. electric drive unit according to claim 8, which is characterized in that each fifth line star-wheel (P5) is respectively by described 4th tooth engagement (ZE4) and by the 6th tooth engagement (ZE6) with third sun gear (S3) by dual holding, wherein, it is described Second sun gear (S2) and the third sun gear (S3) are arranged coaxially with each other, and here, second sun gear (S2) With in two output shafts (A1, A2) the first output shaft (A1) act on connect, and the third sun gear (S3) and two it is defeated The second output shaft (A2) effect connection in shaft (A1, A2).

10. electric drive unit according to claim 8, which is characterized in that wherein each second planetary gear (P2) at least portion Ground is divided radially to sink to respectively in the gap between the fourth line star-wheel (P4) being separated from each other in peripheral side.